When producing an IC device or other electronic device having a semiconductor integrated circuit, the integrated circuit is subjected to an operation test not only at the stage of the finished product after dicing, wire bonding, packaging, and other steps (post-process), but also usually at the stage of the semiconductor wafer (pre-process). Due to this, an improvement in the production yield is achieved.
In a test in this wafer state, a large number of contact pins provided at a probe card are brought into electrical content with the terminals formed in the wafer to transfer electrical signals for testing.
As the contact pins used for a test in this wafer state, pins obtained by plating a gold alloy or other low hardness metal material on the surface of a base material made of a steel material so as to improve the closeness of contact with the terminals of the wafer at the time of contact have been known in the past.
However, such contact pins had the problems that since the metal materials are soft, the pins easily deformed upon contact with the terminals and therefore were inferior in terms of durability.
As opposed to this, as contact pins superior in durability, pins obtained using for example tungsten alloy or another high hardness metal material to make the pins themselves have been known in the past.
Using, an oxide film is formed over the terminals of a wafer. At the time of contact, the contact pins break this oxide film and reach the terminals themselves. At this time, since such contact pins are overall made of high hardness materials, the area of contact with the oxide film inevitably becomes larger, so there was the problem that the pushing force applied at the time of contact could not efficiently contribute to breakage of the oxide film and stable contact between the contact pins and terminals was difficult to secure. Further, in a probe card having several thousand contact pins, sometimes the pushing force applied at the time of contact with the terminals caused the probe card itself to bend. In such a case, poor contact with the terminals of the wafer easily occurs, so contact pins enabling stable contact with the terminals to be secured with a smaller pushing force have been desired.